There's a school of thought that argues you should not disagree with someone if you want to persuade them of your point of view. There's a case, made in a book called Yes, And… that you should amplify the goodwill by amplifying a sense of agreement and collaboration.
The authors of Yes, And… come from Chicago's Second City improv comedy club. "The theatre troupe presents ensemble-based, improvisational comedy. Its actors team up to co-write every performance in spontaneous collaboration. Second City also teaches its cooperative, improvisational – or “improv” – techniques in its corporate consultancy work. Nissan, Motorola, Google, Nike and other firms send employees to study its improv collaboration, fast responses and active listening methods. As hierarchies prove increasingly less effective and businesses grow more fluid, only the most nimble and creative will prevail.
– Improv springs from two words, “yes, and.” When someone offers an idea, respond “yes” to welcome the concept. Then say “and” before reacting. This attitude opens your consciousness to infinite possibilities. Saying “yes, and” means exploring every idea that arises, including ideas in danger of being “judged, criticised and rejected too quickly.” This lets you explore potential new paths without self-consciousness, fear or embarrassment. When people say “yes, and,” they can work together openly."
The video above asserts another perspective on the use of language to persuade. It may seem contrary to the proposition above, but it's interesting and worth considering. How can you use 'but' and 'so' to make a persuasive case. I've been watching this guy's videos off and on for years and often find them useful - interesting how he has evolved his presentation over time.
You can read an abstract of the Yes, And book here: